Quoted from The New Jim Crow by Michelle Alexander:
The backlash against the gains of African Americans in the Reconstruction Era was swift and severe. As African Americans obtained political power and began the long march toward greater social and economic equality, whites reacted with panic and outrage. Southern conservatives vowed to reverse Reconstruction and sought the “abolition of the Freedmen’s Bureau and all political instrumentalities designed to secure Negro supremacy.” Their campaign to “redeem” the South was reinforced by a resurgent Ku Klux Klan, which fought a terrorist campaign against Reconstruction governments and local leaders, complete with bombings, lynchings, and mob violence.
The terrorist campaign proved highly successful. “Redemption” resulted in the withdrawal of federal troops from the South and the effective abandonment of African Americans and all those who had fought for or supported an egalitarian racial order. The federal government no longer made any effort to enforce federal civil rights legislation, and funding for the Freedmen’s Bureau was slashed to such a degree that the agency became virtually defunct.
Once again, vagrancy laws and other laws defining activities such as “mischief” and “insulting gestures” as crimes were enforced vigorously against blacks. The aggressive enforcement of these criminal offenses opened up an enormous market for convict leasing, in which prisoners were contracted out as laborers to the highest private bidder. Douglas Blackmon, in Slavery by Another Name, describes how tens of thousands of African Americans were arbitrarily arrested during this period, many of them hit with court costs and fines, which had to be worked off in order to secure their release. With no means to pay off their “debts,” prisoners were sold as forced laborers to lumber camps, brickyards, railroads, farms, plantations, and dozens of corporations throughout the South. Death rates were shockingly high, for the private contractors had no interest in the health and well-being of their laborers, unlike the earlier slave-owners who needed their slaves, at a minimum, to be healthy enough to survive hard labor. Laborers were subject to almost continual lashing by long horse whips, and those who collapsed due to injuries or exhaustion were often left to die.
Convicts had no meaningful legal rights at this time and no effective redress. They were understood, quite literally, to be slaves of the state. The Thirteenth Amendment to the U.S. Constitution had abolished slavery but allowed one major exception: slavery remained appropriate as punishment for a crime.
Alexander, Michelle (2012-01-16). The New Jim Crow (pp. 30-31). Perseus Books Group. Kindle Edition.